Stay-bolt structure.



B. E. D. STAFFORD & E. l. DODDS.

STAY son STRUCTURE. APPLICATION FILED FEB. 29. l9l6- 1,216,621. Paflmted Feb. 20, 1917.

I W Auom o" BENJAMIN E. D. STAFFORD AND ETI-IAN I. DODDS, OF PITTSBURGI-I, PENNSYLVANIA,

ASSIGNORS TO FLANNERY BOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA.

STAY-BOLT STRUCTURE.

Specification of Letters Patent.

Patented Feb. 20, 1917.

Application filed February 29, 1916. I Serial No. 81,260.

To all whom it may concern:

Be it known that We, BENJAMIN E. D. STAFFORD and ETHAN I. DODDS, citizensof the United States, and residents of; Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Stay-Bolt Structures; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements'in stay bolt structures; the object of the invention being to provide simple means for coupling the spherical or rounded head of a stay bolt to the outer sheet of ai boiler, in

such manner that adequate play or movement of the bolt in all directions will be afforded to compensate for expansion and contraction of. the boiler sheets, and at the same time guard against leakage and also expose the tell-tale hole in the outer portion of the bolt.

With this and other objects in view, the

invention consists in certain novel featuresof construction and combinations of parts as hereinafter set forth and pointed out in the claims.

In the accompanying drawings; Figurel is a view partly in section and partly in elevation, illustrating one embodiment of our invention, and Fig. 2 is a similar view showing a modification.

1 represents the inner and 2 the outer boiler sheets,the latter being provided with a bolt hole 3, a portion of the wall of which forms a curved bearing 4 for the rounded or spherical head 5 of a stay bolt 6,the inner end of the latter being secured to the inner boiler sheet 1 in the usual manner. In the embodiment of our invention shown in Fig. 1 of the drawing, the head of the bolt is made spherical in form and provided with a driving slot 7 ,with which the outer end of a tell-tale hole 8 communicates.

The upper portion of thehead of the bolt is engaged by a curved seat 9 formed on an annular yielding cap 10,said cap being so formed that it will not completely inclose the bolt head, but will expose the outer extremity thereof and thus leave the outer end of the tell-tale hole open or exposed.

.The yielding cap 10 is formed with a bowed portion 11 which gives resiliency to The-:cap 10 serves not only to afford a yielding universal connection of the bolt head to the outer boiler sheet, but it also prevents leakage past said bolt head, and the chamber 14 formed by the bowed portion also constitutes a receptacle for stiff lubricant which affords a suitable packing and also lubricates the bearing faces of the bolt head. 7

In the embodiment of our invention shown in Fig. 2, a rounded bolt head 15 somewhat flattened as compared to the bolt head shown in Fig. 1, is employed. In Fig. 2, the yielding cap 16 is made annular in form. with its upper portion bowed inwardly to form a yielding bearing member 17 pressing against the outer end of the rounded bolt-head 15 and curved to conform to the contour of the latter. The outer edge of the cap 16 rests fiat against the outer face of the outer boiler sheet 2 and is welded to the latter as indicated at 18. This form of cap exposes the outer end of the tell-tale hole in the bolt and it also affords a chamber 18 in which lubricating packing may be placed.

Having fully described ourinvention what we claim as new and desire to secure by Letters-Patent, is

1. In a stay bolt structure, a yielding cap having a member against which the outer portion of the rounded head of a bolt may seat, said cap having a part to be seated against the outer face of the outer boiler sheet and adapted to be secured thereto.

2. In a stay bolt structure, the combination with a boiler sheet, of a yielding cap having a member to engage an outer end portion of the rounded head of a stay bolt, and having a base portion to rest against the outer face of said boiler sheet, said base portion of the cap being welded to the boiler sheet.

3; In a stay bolt structure, a yieldingcap' comprising an annular structure of spring metal having a part to engage the end portion of the rounded head of a stay bolt and having a base portion adapted to be welded to an outer boiler sheet, said cap having a chamber to contain lubricating packing.

at. In a stay bolt structure, the combination with an outer boiler sheet having a bearing therein, and a stay bolt having a rounded head to engage said bearing, said stay bolt also having a tell-tale hole, of a yielding cap comprising an annular structure having a part bearing against the outer end of the bolt head and exposing'the tell-tale hole in the latter, said cap structure also having a part welded to the outer face of the outer boiler sheet.

5. In a stay bolt structure, a yielding cap comprising an intermediate bowed portion, a member projecting from one end of said bowed portion and adapted to engage the outer end of the head of a stay bolt, and a base member adapted to lie flat against the outer face of the outer boiler'sheet and to be welded thereto.

6. In a stay bolt structure, the combination with a boiler sheet and a stay bolt having a head, of an annular flexible cap to en circle the head of the bolt, said cap comprising a part secured to the boiler sheet and a part pressing against the stay bolt in an ingvard direction parallel with the axis of the olt.

7. In a stay bolt structure, an annular flexible cap adapted to encircle the head of a stay bolt and comprising oppositely disposed connected members, the free edge of one of said members adapted to be secured to a boiler sheet and the free edge of the other member disposed to press against the head of a stay bolt passing through said boiler sheet, in a direction approximately parallel with the axis of the bolt.

8. In a stay bolt'structure, the combination with a boiler sheet and a stay bolt having a head, of a flexible metal cap secured at one edge to the boiler sheet and at its other edge engaging the head of the stay bolt to normally press against the same in a direction approximately parallel with the axis of the bolt.

9. In a stay bolt structure, the combination with a boiler sheet and a stay bolt having a head, of an annular flexible metal cap encircling the head of the stay bolt and normally pressing at one edge against the same in a direction approximately parallel with the axis of the bolt, the other edge of said annular cap being secured to the boiler sheet.

In testimony whereof, we have signed this specification in the presence of two subscribing witnesses.

BENJAMIN E. D. STAFFORD. ETHAN I. DODDS. Witnesses:

F. H. ALmsoN, EDWIN S. RYoE.

Copies of this patent may be obtained for five cents each, byaddressing the Commissioner of Patents,

Washington, D. G. 

